Your dog takes a few steps, then suddenly skips on one back leg. A second later, everything looks normal. You wonder if you imagined it.

You didn't. That skipping gait is one of the most recognizable signs of medial patellar luxation, one of the most common orthopedic conditions in dogs. Understanding what's actually happening in your dog's knee makes it much easier to know what to do next.

What it is: Medial patellar luxation (MPL) means your dog's kneecap (patella) slips out of its normal groove and moves toward the inside of the leg.Who gets it: Mostly small and toy breeds, though any dog can be affected.How common: MPL is diagnosed in about 7% of puppies, according to the American College of Veterinary Surgeons.What happens: Some dogs skip occasionally with no obvious pain. Others develop persistent limping, stiffness, or a bowed-leg appearance.

Key takeaways

• The kneecap slips inward: In MPL, the patella moves toward the inside of the knee, not outward.
• It's mostly genetic: The condition is inherited in most dogs, not caused by injury or lifestyle.
• Small breeds are most at risk: Chihuahuas, Pomeranians, and Maltese are among the most commonly affected.
• It ranges from mild to severe: Four grades describe how often the kneecap slips and how bad the impact is.
• Surgery isn't always needed: Mild cases are often managed without surgery, especially in dogs with few symptoms.
• Arthritis is a long-term risk: Left untreated in moderate to severe cases, MPL can lead to permanent joint damage.

How your dog's kneecap is supposed to work

The patella is a small bone embedded in the tendon that runs along the front of your dog's knee. It sits inside a groove at the end of the thighbone (femur) and slides smoothly up and down when your dog moves.

This movement acts like a pulley system, helping the large thigh muscles straighten the leg efficiently. When everything is aligned correctly, the kneecap stays centered in its groove with each step.

In a dog with MPL, the groove is often too shallow, or the bones of the leg are angled in a way that pulls the kneecap off track. Over time, this repeated displacement wears down the joint and can cause arthritis.

What causes MPL in dogs

Abnormal bone development

The most common cause is a skeletal alignment problem that develops as the puppy grows. The thighbone, shinbone, or hip socket may form at slightly abnormal angles.

This pulls the entire "extensor mechanism" (the muscle-tendon-kneecap system) off-center. As Cornell University's College of Veterinary Medicine explains, dogs with MPL typically have a shallow femoral groove or general limb malalignment.

Genetic predisposition

MPL is considered an inherited condition in most dogs. Certain breeds carry genes that make the condition far more likely, which is why some breeds appear in veterinary offices with MPL at much higher rates than others.

According to research, MPL is 12 times more common in small dogs than in large dogs.

Trauma

In some cases, a fall, collision, or leg injury can damage the soft tissue structures around the knee, allowing the kneecap to shift. This is less common than the developmental cause but does occur, particularly in adult dogs with no prior history of the condition.

Which breeds are most commonly affected

Small and toy breeds are most at risk for MPL. The following breeds are among those most frequently diagnosed:

• Chihuahua
• Pomeranian
• Maltese
• Miniature and Toy Poodle
• Yorkshire Terrier
• Bichon Frise
• Boston Terrier
• French Bulldog

Large breeds can develop MPL too, though it's less common. According to the American College of Veterinary Surgeons, the condition is diagnosed primarily in small dogs but is increasingly recognized in larger breeds as well.

For a full breakdown of how the condition presents differently based on size, see how MPL differs in small vs large breeds.

What MPL looks like from the outside

The signs vary considerably depending on how severe the luxation is. Some dogs show almost no symptoms for years. Others are noticeably uncomfortable from an early age.

Common signs include:

• Intermittent skipping: The dog lifts one back leg for a few steps, then puts it back down as if nothing happened. This is the classic MPL presentation.
• Occasional leg shaking or extension: Some dogs kick their leg out to the side to pop the kneecap back into place.
• Lameness after rest: Stiffness when getting up after sleeping or lying down.
• Reluctance to exercise or jump: The dog avoids activities that stress the knee.
• Bow-legged appearance: In young puppies with more severe MPL, the rear legs may appear bowed outward.

For a complete list of what to watch for, visit signs and symptoms to watch for.

How MPL is diagnosed

Your veterinarian will diagnose MPL through a physical examination. The vet manually palpates the knee while flexing and extending the joint to feel whether the kneecap slides out of the groove and back in again.

X-rays may be taken to evaluate the degree of bone deformity, the depth of the femoral groove, and whether any arthritis is already present.

The examination assigns your dog a grade from 1 to 4, which reflects how easily the kneecap displaces, how often it stays out, and whether it returns to the groove on its own.

For a clear explanation of what each grade means for your dog's treatment and outlook, read about the four grades of patellar luxation.

Once your dog has a confirmed grade, the next decision is whether treatment is needed and what kind. For guidance on when surgery is necessary, including which grades typically require intervention and which can be managed conservatively, that article walks through the decision in full.

How serious is MPL?

The severity depends heavily on the grade and how quickly it progresses.

Grades 1 and 2 often have good outcomes with conservative management. Grades 3 and 4 typically require surgery for meaningful improvement.

Can MPL be prevented?

Because MPL is primarily genetic, true prevention is not possible in dogs who carry the relevant genes. However, early detection matters.

For puppies from at-risk breeds, regular veterinary checkups from an early age allow the condition to be identified and graded before it progresses or causes joint damage.

For information on reducing risk in young dogs and what early intervention looks like, see whether MPL can be prevented in puppies.

When MPL affects both knees

MPL occurs in both knees in many dogs. Some dogs have it in only one knee; others have different grades in each knee.

Bilateral MPL (both knees affected) is common, particularly in small breeds. It changes the treatment planning and recovery process.

For more on how bilateral cases are managed, see what bilateral MPL means and how to tell if your dog has MPL.

Frequently asked questions

Is MPL painful for dogs?

It depends on the grade. Mild MPL (Grade 1 or 2) often causes little obvious pain, though the joint is still being stressed with each luxation. More severe grades (3 and 4) typically cause persistent lameness and discomfort. Long-term, repeated luxation causes arthritis, which becomes increasingly painful over time.

How do I know if my dog has MPL or just hurt their leg?

The intermittent skipping pattern is the biggest clue. If your dog skips, then resumes walking normally within a few steps, MPL is a likely explanation. A traumatic leg injury typically causes consistent limping rather than this on-and-off pattern. Your vet can confirm through a physical exam.

My dog was just diagnosed with MPL. Does that mean surgery right away?

Not necessarily. Grade and symptom severity guide the treatment recommendation. Many dogs with Grade 1 or 2 MPL are managed with physical therapy, weight management, and monitoring rather than immediate surgery. Your vet will assess which path is appropriate for your dog specifically.

Can a dog live a normal life with MPL?

Many dogs do, particularly those with low-grade MPL. Dogs with higher grades may have quality-of-life limitations that surgery can significantly improve. The key is getting an accurate grade assessment and following the treatment plan your vet recommends.

MPL is one of the most common orthopedic conditions in small dogs, but being common doesn't mean it's simple. The range from mild and barely noticeable to severe and debilitating is wide, and the treatment path depends entirely on where your dog falls within it. A clear grade and an honest conversation with your vet is the right starting point for every MPL case.

Resources

• American College of Veterinary Surgeons. Patellar Luxations. acvs.org
• Cornell University College of Veterinary Medicine. Patellar Luxation. vet.cornell.edu
• VCA Animal Hospitals. Luxating Patella in Dogs. vcahospitals.com

Not every dog with MPL needs surgery. For some dogs, non-surgical management keeps symptoms under control well enough that surgery never becomes necessary. For others, it's a bridge that buys time until surgery is appropriate or feasible.

Knowing what non-surgical treatment actually involves, which dogs it's suitable for, and what the warning signs of failure look like helps you make a genuinely informed decision alongside your vet.

Quick answer: Conservative management for MPL works best for Grade 1 and mild Grade 2 dogs with infrequent symptoms. It includes weight management, physical therapy, activity modification, anti-inflammatory medication when needed, and joint supplements. It manages symptoms but doesn't correct the underlying anatomy. When symptoms worsen or become frequent, surgery typically becomes the appropriate next step.

Key takeaways

• Conservative management is a real option for Grade 1 and mild Grade 2 dogs, not a second-best fallback.
• Weight control is the single most impactful non-surgical intervention: less weight means less joint stress.
• Physical therapy builds the muscle support around the knee that partially compensates for joint instability.
• Non-surgical treatment doesn't cure MPL: the kneecap will still slip, but symptoms can be managed.
• Hydrotherapy allows exercise without joint loading, making it ideal for MPL-affected dogs.
• Monitor for progression: if symptoms worsen despite consistent management, surgery becomes appropriate.

Which dogs are suitable for non-surgical management

Grade determines whether conservative treatment is a realistic long-term path.

Grade 1: The kneecap only slips when manually pressed and returns immediately. Most Grade 1 dogs have no visible symptoms. Conservative monitoring, weight management, and optional supplements are standard. Surgery is rarely indicated.

Mild Grade 2: The kneecap slips occasionally during movement but returns on its own. Symptoms are intermittent. Many Grade 2 dogs manage well for years without surgery. Conservative management is the standard starting point unless symptoms are frequent or the dog's quality of life is clearly affected.

Grade 2 with frequent symptoms: Still a candidate for a trial of conservative management, but more likely to need surgery eventually. Close monitoring is essential.

Grade 3 and 4: Conservative management is not adequate for these grades. The kneecap is out most or all of the time, and the joint degrades continuously without surgical correction. For Grade 3 and 4, surgery is the appropriate recommendation.

For the full grade-by-grade surgery decision framework, see when non-surgical management is no longer enough.

Understanding which grade your dog has is the foundation of the treatment decision. For a clear breakdown of what Grades 1 through 4 mean in terms of symptoms and treatment path, see which grades are suitable for non-surgical treatment.

Step 1: Weight management

The most controllable and most impactful non-surgical intervention is maintaining a healthy body weight.

Every extra pound a dog carries places additional mechanical load on an already unstable joint. For a dog whose kneecap is already predisposed to slipping, excess weight increases the frequency of luxation events and accelerates cartilage wear.

What this looks like in practice:

• Feed measured portions of a high-quality diet rather than free-feeding
• Account for treats in the daily calorie total
• Weigh your dog every one to two months and track the trend
• Ask your vet to assess body condition score at every visit
• Discuss a targeted weight loss plan if your dog is already overweight

Even modest weight reduction in an overweight dog with Grade 2 MPL can produce noticeable improvement in symptoms.

Step 2: Physical therapy and muscle strengthening

The muscles around the knee, particularly the quadriceps, provide dynamic stability that partially compensates for the anatomic looseness causing luxation. Building and maintaining this muscle mass is a core component of non-surgical MPL management.

A Frontiers in Veterinary Science review (2026) on canine MPL rehabilitation notes that quadriceps strengthening and hip-focused exercise contribute meaningfully to patellar stability in dogs.

Exercises that help:

• Leash walks on even terrain: Regular, controlled walking builds overall hindlimb strength without excessive joint stress
• Cavaletti poles (low): Walking over low obstacles encourages deliberate leg placement and builds proprioception
• Balance exercises: Standing on a balance disc or wobble board activates stabilizing muscles around the knee
• Sit-to-stand repetitions: Gentle, controlled weight-bearing exercise for the quadriceps

Exercises to avoid:

• Fetch and rapid direction changes
• Jumping on and off furniture
• Stairs with steep incline
• Running on hard surfaces for extended periods

For dogs with more significant symptoms, a referral to a certified canine rehabilitation therapist is worth considering. A therapist can design a customized program and monitor progress over time.

For exercises that also benefit non-surgical cases, see rehabilitation exercises that also help non-surgical cases.

Step 3: Hydrotherapy

Hydrotherapy (swimming or underwater treadmill therapy) allows a dog to exercise without placing significant weight on the affected joint. The buoyancy of water reduces joint loading while still engaging the muscles.

Benefits for MPL dogs managed conservatively:

• Builds quadriceps and hip muscle strength without the impact of walking on land
• Reduces inflammation in the joint through the warmth and resistance of water
• Provides mental stimulation and exercise for dogs who need to stay active but can't run freely

Underwater treadmill sessions typically run 20 to 30 minutes, one to three times per week, depending on the dog's condition. Many veterinary rehabilitation centers offer this service.

Step 4: Activity modification

Reducing the mechanical stress on the knee during daily life is an important component of conservative management.

Practical modifications:

• Use ramps instead of stairs where possible
• Lift your dog in and out of the car rather than letting them jump
• Use furniture ramps if your dog sleeps on a sofa or bed
• Choose soft ground for walks (grass, dirt paths) over hard pavement
• Shorten but don't eliminate walks on days when the dog appears sore

Activity modification doesn't eliminate the condition, but it reduces the number and force of luxation events, which slows cartilage wear.

Step 5: Anti-inflammatory medication

During flare-ups, when symptoms are more pronounced than usual after a long walk or active period, short-course anti-inflammatory medication can reduce pain and swelling.

Common options your vet may recommend:

• NSAIDs (non-steroidal anti-inflammatory drugs): Such as carprofen, meloxicam, or grapiprant. Used short-term during flare-ups, or in some cases on a longer-term basis for dogs with established secondary arthritis.
• Omega-3 fatty acids: At therapeutic doses, fish oil has demonstrated anti-inflammatory effects in dogs. Can be used continuously rather than just during flare-ups.

Do not give human NSAIDs (ibuprofen, naproxen, aspirin) to dogs. These are toxic to dogs even at low doses.

Long-term NSAID use should be monitored with periodic bloodwork to assess kidney and liver function, particularly in older dogs.

Step 6: Joint supplements

Joint supplements don't correct MPL, but they support the health of the cartilage and joint fluid in a knee that is being repeatedly stressed by luxation events.

Commonly used supplements for MPL dogs:

• Glucosamine and chondroitin: Support cartilage maintenance and synovial fluid quality
• Omega-3 fatty acids (EPA/DHA from fish oil): Reduce inflammatory activity in the joint
• Green-lipped mussel: A natural source of omega-3s and glycosaminoglycans
• Adequan injections (polysulfated glycosaminoglycan): A veterinary injectable that supports cartilage and has anti-inflammatory effects; administered by a vet

Always confirm supplement choice and dosing with your vet, as quality varies significantly between brands and not all products marketed for joint health have equal evidence behind them.

Step 7: Bracing

Dog knee braces for MPL provide external support to the joint during movement. They can reduce discomfort in mild cases and give a dog more stability during activity.

Their limitations are real: the patella is small and mobile, and a brace is unlikely to prevent it from slipping during movement. They manage symptoms rather than address the cause. For a full comparison of bracing versus surgery and when each is appropriate, see how braces compare to surgery as an option.

Signs that conservative management is no longer working

Conservative management requires consistent monitoring. The signs that the plan is no longer adequate:

• Skipping or limping episodes are becoming more frequent
• The dog's recovery after episodes takes longer
• The dog is avoiding activities it previously managed
• Muscle atrophy in the affected thigh is becoming more visible
• The dog shows pain on gentle manipulation of the knee at vet visits
• A grade reassessment confirms progression to a higher grade

When any of these occur, revisit the surgical conversation with your vet. The decision to move from conservative to surgical management is not a failure. For many dogs, it's simply the next appropriate step.

For guidance on which symptoms indicate treatment is needed and when conservative care isn't enough, see symptoms that indicate treatment is needed.

Frequently asked questions

How long can a dog stay on conservative management?

There's no fixed answer. Some Grade 1 and mild Grade 2 dogs are managed conservatively for years with minimal progression. Others advance to Grade 3 within 12 to 18 months. The key is consistent monitoring: a reassessment every 6 months allows your vet to track whether the grade is stable or advancing.

Will non-surgical management prevent arthritis?

Not entirely. Every luxation event, no matter how brief, causes some stress on the joint cartilage. Conservative management slows this process by reducing the frequency of luxation and supporting joint health, but it doesn't eliminate it. Dogs managed conservatively long-term are more likely to develop arthritis than those whose structural problem is corrected surgically before significant damage accumulates.

Can I just give supplements and skip the other steps?

Supplements alone are insufficient for managing MPL. Weight control and physical therapy produce more meaningful functional benefit than supplements in isolation. Supplements work best as one component of a complete management plan.

Is it safe for a dog on conservative management to exercise?

Yes, but the type and intensity of exercise matters. Low-impact, controlled exercise builds the muscle support around the knee and is beneficial. High-impact activity (fetch, jumping, rough play) stresses the joint and increases luxation frequency. Walk your dog regularly; just choose the terrain and pace thoughtfully.

Non-surgical management is not a lesser choice for the dogs it suits. For a Grade 1 or mild Grade 2 dog managed consistently with weight control, physical therapy, and appropriate activity, years of comfortable, active life are achievable. The key is knowing when the plan is working and recognizing when the signs are telling you it's no longer enough.

Resources

• Cornell University College of Veterinary Medicine. Patellar Luxation. vet.cornell.edu
• Frontiers in Veterinary Science. Translational Rehabilitation Strategies for Canine MPL. frontiersin.org
• Canine Rehab OC. Medial Patellar Luxation (MPL). caninerehaboc.com

Rehabilitation after MPL surgery is what turns a successful operation into a fully functional leg.

Surgery corrects the structural problem. Rehab rebuilds the muscle that was lost during the lameness period, restores normal movement patterns, and prepares the joint for the activity your dog will return to. Without structured rehab, dogs take longer to recover and often return to lower function than those who follow a proper plan.

Quick answer: Rehab after MPL surgery progresses through three phases. Weeks 1 to 2 focus on passive range-of-motion exercises and gentle movement. Weeks 3 to 6 introduce sit-to-stands, short leash walks, and massage. Weeks 6 to 12 add hydrotherapy, balance exercises, and hill walks. Each phase depends on confirmation from your vet before progressing.

Key takeaways

• Rehab accelerates recovery and improves outcomes compared to rest alone.
• Passive range-of-motion exercises start in week 1 or 2 to prevent stiffness.
• Sit-to-stands are the most important active exercise for rebuilding quadriceps strength.
• Hydrotherapy allows full muscle engagement without joint loading: ideal for the middle recovery phase.
• Hill walks build hindlimb strength more efficiently than flat-ground walking.
• Never push through pain: if limping worsens after an exercise session, reduce intensity.

Why rehab matters after MPL surgery

When a dog has MPL, they've often been sparing the affected leg for weeks or months before surgery. The thigh muscles on that side are already smaller and weaker than the other leg.

After surgery, strict rest further reduces muscle mass. By the time exercise begins, significant atrophy is typical. Without targeted rehabilitation, the leg may recover to adequate function but not full strength or confidence.

A Frontiers in Veterinary Science review (2026) on canine MPL rehabilitation notes that quadriceps strengthening and hip-focused exercise produce meaningful improvements in patellar stability and limb function. Structured rehab gives your dog a better outcome than rest and leash walks alone.

For the full recovery timeline that determines when each exercise phase begins, see the full MPL surgery recovery timeline.

Phase 1 (weeks 1 to 2): passive exercises and gentle movement

During the first two weeks, the repair site is fragile. Active resistance exercise is off the table. Passive exercises protect the joint while preventing it from stiffening.

Passive range-of-motion (PROM)

PROM involves gently moving the leg through its natural range without your dog actively participating. The goal is to maintain flexibility in the joint and prevent the scar tissue from tightening.

How to do it:

1. Have your dog lie on their side, affected leg facing up
2. Support the leg at the hip and just below the knee
3. Slowly and gently flex (bend) the knee until you feel light resistance
4. Hold for 3 to 5 seconds, then slowly extend the leg back out
5. Repeat 10 to 15 times, twice daily

Critical rules:

• Move slowly and stop if your dog shows any pain response (flinching, vocalizing, pulling away)
• Never force the joint past its comfortable range
• The leg should move like a gentle pendulum, not be pushed aggressively

Icing

Applying a cold pack wrapped in a cloth to the surgical site for 10 to 15 minutes after any handling or exercise reduces inflammation. Use two to three times daily in the first week.

Phase 2 (weeks 3 to 6): building early strength

Once your vet confirms healing is on track, active exercises begin. The focus is rebuilding the thigh muscles that support the knee.

Sit-to-stands (puppy squats)

Sit-to-stands are the most important exercise in MPL rehabilitation. They directly target the quadriceps, which are the primary muscle group that stabilizes the repaired kneecap.

How to do it:

1. Ask your dog to sit in a controlled position
2. Cue them to stand up slowly
3. Once standing, cue them to sit again
4. Repeat 5 to 10 repetitions, two to three times daily

Start with five repetitions and increase gradually as your dog builds strength and tolerance.

What to watch for: Your dog should use both back legs equally during the sit-to-stand. If they consistently avoid using the operated leg (pushing off the good leg only), bring this to your vet or rehab therapist's attention.

Short leash walks

Short, controlled leash walks on flat, even ground are introduced from week 3. The purpose is weight-bearing and muscle use, not cardiovascular exercise.

Starting protocol:

• 5 minutes per walk, two to three times daily
• Flat surface only (grass or packed dirt preferred over pavement)
• Slow pace; allow the dog to dictate the speed
• Short leash (2 to 3 feet) for control

Increase duration by 5 minutes per week if your dog is tolerating walks without increased limping after the session.

Gentle massage

Light massage of the thigh muscles on the operated side improves circulation, reduces muscle tension, and encourages your dog to use the leg more confidently.

Technique: Use gentle, circular strokes along the thigh muscle (not directly over the incision) for 3 to 5 minutes once or twice daily. Your dog should find this comfortable and calming.

For information on how these exercises also help non-surgical MPL cases, see exercises that also help non-surgical cases.

Phase 3 (weeks 6 to 12): progressive loading and coordination

After the 6 to 8 week recheck confirms good healing, exercise intensity increases. This phase focuses on rebuilding full strength, coordination, and confidence.

Hydrotherapy (underwater treadmill or swimming)

Hydrotherapy is one of the most effective rehabilitation tools after MPL surgery. Water buoyancy reduces the mechanical load on the joint while water resistance provides meaningful muscle engagement.

Benefits:

• Allows the dog to exercise through a full range of motion with less pain
• Builds muscle faster than land walking at the same effort level
• Warms the joint and reduces stiffness
• Ideal for dogs who are reluctant to use the leg on land

Types:

• Underwater treadmill: The dog walks on a submerged treadmill in a water chamber. The water level is set to reduce joint loading while the walking movement builds muscle. Most commonly available at veterinary rehabilitation centers.
• Controlled swimming: Pool or tank swimming. More cardiovascular than the underwater treadmill and introduces more rotational movement in the limb. Usually introduced after the treadmill phase.

Frequency: one to two sessions per week to start, increasing as your dog builds strength.

Balance exercises

Balance work activates the stabilizing muscles around the knee and improves proprioception (the dog's sense of where their limb is in space).

Exercises:

• Balance disc or wobble board: Have your dog stand with two or four paws on an unstable surface for 30 to 60 seconds. The instability activates the stabilizing muscles without high-impact loading.
• Cavaletti poles: Walk your dog slowly over a series of low poles spaced at walking stride length. This encourages deliberate leg placement and builds proprioceptive awareness.
• Weight shifting: Gently push your dog's weight side to side while they stand, encouraging them to shift weight onto the operated leg.

Controlled hill walks

Gentle, slow hill walking is introduced in the later stages of Phase 3. Walking uphill engages the quadriceps and hindlimb muscles significantly more than flat-ground walking.

Protocol from Animal Clinic of Billings: Walk the dog slowly up, down, and across a gentle hill with the surgical leg on the downhill side. This increases strength and muscle mass while improving range of motion and balance.

Use a hill that's gradual enough that you can walk it comfortably yourself. Steep hills or running on hills are not appropriate at this stage.

Signs that rehab should be paused or adjusted

Not every day of rehab goes smoothly. Know when to pull back:

• Increased limping after exercise: The dog was walking well but is now more lame than before the session. Reduce duration and intensity, and contact your vet if the limping persists beyond 30 minutes after the session ends.
• Swelling or heat at the knee after exercise: The joint is being overworked. Reduce activity, ice the knee, and consult your vet.
• Refusal to use the leg: A sudden shift to non-weight-bearing after a period of normal use warrants a vet visit.
• Pain response during exercises: Flinching, vocalizing, or pulling away during PROM or active exercises means you're at or past the dog's comfortable limit.

For a full overview of what post-surgical complications look like and when to escalate, see signs that rehab should be paused or adjusted.

Working with a canine rehabilitation therapist

While many owners successfully manage rehab at home with veterinary guidance, a certified canine rehabilitation therapist (CCRT or CCRP) offers meaningful advantages:

• Customized exercise plan based on your dog's specific surgery, grade, and progress
• Access to equipment not available at home (underwater treadmill, laser therapy, neuromuscular electrical stimulation)
• Hands-on assessment of gait, muscle mass, and joint range at each session
• Immediate adjustment if the dog shows pain or altered movement

Even one or two sessions with a rehab therapist to establish the home program and correct technique is valuable if you can't do regular sessions.

How rehab changes for bilateral cases

When both knees have been operated on, the exercise plan must account for the fact that both legs are recovering simultaneously.

In the early phases, the dog has no good leg to rely on. PROM for both legs, assisted standing, and very short controlled walks are used with additional support (sling for the hindquarters) if needed.

As recovery progresses, the protocol is similar but the total duration of each session may be shorter to avoid fatiguing both legs simultaneously.

For how the overall rehab timeline differs in bilateral cases, see how rehab differs when both knees are recovering.

How rehab contributes to long-term success rates

The published MPL surgery success rates discussed in the research literature assume reasonable post-operative management. Dogs who receive structured rehabilitation achieve better functional outcomes and lower recurrence rates compared to those with unguided rest alone.

For the data on how rehab influences overall surgical outcomes, see how rehab contributes to surgical success rates.

Frequently asked questions

When can I start hydrotherapy after MPL surgery?

Most dogs can begin hydrotherapy at 4 to 6 weeks post-surgery, once the incision is fully healed and early bone healing is confirmed. Your vet will advise based on your dog's specific progress. Starting before the incision is fully healed risks wound contamination.

Can I do rehab at home without going to a specialist?

Yes. Simple exercises like sit-to-stands, controlled leash walks, PROM, and massage can all be performed at home with your vet's guidance. An initial session with a rehab therapist to establish correct technique is helpful if accessible. The key is consistency: daily exercises performed correctly matter more than occasional specialist sessions.

How many sit-to-stands should I do per day?

Start with 5 repetitions, twice daily. Increase to 10 repetitions per session once your dog is performing them comfortably and without limping afterward. The Animal Clinic of Billings rehabilitation protocol recommends continuing sit-to-stands from week 6 through the full recovery period, as they're the most effective single exercise for rebuilding quadriceps strength after MPL surgery.

My dog won't do the exercises. What do I do?

Use food motivation. Have a treat at nose level in front of your dog during sit-to-stands to guide the movement. For PROM, start with very brief sessions immediately after pain medication has had time to take effect, when your dog is most comfortable. Never force the exercises. If your dog consistently refuses, discuss the approach with your vet or a rehab therapist.

Rehabilitation isn't the dramatic part of MPL treatment. The surgery gets all the attention. But it's the quiet, consistent daily work of the recovery phase, the sit-to-stands at 7am, the 10-minute leash walk in the rain, the hydrotherapy sessions, that determines how fully your dog comes back. The surgery creates the potential. Rehab realizes it.

Resources

• Animal Clinic of Billings. Canine Rehabilitation After Luxating Patella Surgery. animalclinicofbillings.com
• Frontiers in Veterinary Science. Translational Rehabilitation Strategies for Canine MPL. frontiersin.org
• TPLO Info. Rehab for Dogs After TPLO Surgery. tploinfo.com

"Will the surgery actually work?" is the first question most owners ask once they've decided surgery is the right path.

The honest answer is: for most dogs, yes. MPL surgery has a strong overall success record. But success rates aren't uniform across all grades, and understanding what the published research actually says helps you go into the process with realistic expectations.

Quick answer: MPL surgery has an overall success rate of approximately 90 to 93% across most studies, with lower grades consistently achieving better outcomes than higher grades. Recurrence (the kneecap slipping again after surgery) occurs in roughly 8 to 21% of cases depending on grade, with Grade 4 carrying the highest complication risk. For most dogs, surgery produces meaningful improvement in function and quality of life.

Key takeaways

• Overall success rate is approximately 90 to 93% across published MPL surgery studies.
• Lower grades have better outcomes: Grade 1 and 2 dogs achieve higher success rates than Grade 3 and 4.
• Recurrence happens in roughly 8 to 21% of cases depending on grade and surgical technique.
• Grade 4 carries the highest complication rate but still achieves a 93% overall success rate in major studies.
• Most dogs return to full or acceptable function even when minor complications occur.
• Early surgery improves outcomes: Less joint damage at the time of surgery means a cleaner repair and faster recovery.

What "success" means in MPL surgery research

Before looking at the numbers, it helps to understand what researchers mean by a "successful" outcome in MPL surgery.

Most studies define success as: no catastrophic complication, with the dog returning to full or acceptable function as reported by both the surgeon and the owner. This is measured through a combination of:

• Orthopedic exam findings (pain and lameness scores)
• Owner questionnaires about daily activity, mobility, and comfort
• Radiographic follow-up in some studies

A dog can have minor complications and still be classified as a success if they return to good function. This distinction matters when reading statistics.

What the research shows by grade

Grades 1 and 2: excellent outcomes

Lower-grade MPL surgery consistently achieves the best results. Published data across multiple studies shows recurrence rates below 10% for Grades 1 and 2, and most dogs return to full, normal function within 8 to 12 weeks.

According to a review cited in ResearchGate (2021), approximately 92% of dogs overall were considered sound at follow-up. In Grade 2 cases specifically, success rates above 90% are commonly reported, with many dogs experiencing complete resolution of lameness.

The main reasons lower grades do better:

• Less bone deformity to correct
• Less cartilage damage has accumulated before surgery
• Simpler procedures with lower complication risk
• Younger dogs are more commonly operated on early

For a full explanation of what drives the surgery decision for Grade 2, see how to decide whether surgery is right.

Grade 3: good outcomes, higher complication rate

Grade 3 MPL surgery produces good outcomes in most dogs, but with more variability than lower grades. The kneecap has been out of alignment for longer, meaning more cartilage wear, more secondary muscle atrophy, and sometimes more complex bone correction needed.

Published recurrence rates for Grade 3 are generally in the 8 to 15% range across studies. Most dogs with recurrence experience a lower-grade luxation (Grade 1 or 2) rather than returning to their original grade, and many of these do not require a second surgery.

Grade 4: favorable overall success despite higher complexity

Grade 4 is the most surgically complex form of MPL, and it carries the highest complication rate. But the overall success rate remains strong.

A JAVMA study (Dunlap et al., 2016) of 24 dogs and 29 stifle joints undergoing Grade 4 MPL correction found:

• 24% of joints had major complications
• 21% had recurrence (Grade 2 to 4)
• 93% had an overall successful outcome (full or acceptable return to function)
• Surgeon-assigned pain and lameness scores at final follow-up were below 2 out of 5 for all dogs

A separate Rakuno Gakuen University study (PMC9270935) of Grade 4 corrections found no major or catastrophic complications, with good prognosis across all cases using combined correction techniques.

The takeaway: Grade 4 surgery requires more from both the surgeon and the dog's recovery process, but most dogs still achieve meaningful improvement.

For how grade affects surgical success rates in more detail, see how grade affects surgical success rates.

Recurrence: what it means and how often it happens

Recurrence means the kneecap displaces again after surgery. It's the most common reason a second procedure might be needed.

Importantly, not every recurrence requires surgery. A 2021 review noted that 68% of recurrence cases resulted in Grade 1 MPL, which can often be managed conservatively.

Recurrence is most commonly caused by:

• Insufficient transposition of the tibial tuberosity during the original procedure
• Bone healing complications affecting alignment
• Large-breed anatomy where the forces on the kneecap are greater
• Failure to follow post-operative rest and rehab instructions

Factors that affect your dog's individual outcome

The published success rates are population averages. Your dog's individual outcome depends on several variables:

Age: Younger dogs generally heal faster and have less secondary joint damage at the time of surgery. Older dogs may have slower recovery and more established arthritis.

Weight: Overweight dogs place more stress on the repair during healing. Maintaining a healthy weight before and after surgery is one of the most controllable outcome factors.

Grade and bone deformity: Higher-grade cases with more significant bone rotation or shallow grooves require more complex correction. More complex correction carries more variables.

Breed size: Large breeds have a higher rate of recurrence after surgery compared to small breeds, based on published data. Their greater body weight creates more mechanical force on the repair.

Bilateral surgery timing: Dogs having both knees operated on at the same session (single-session bilateral) face slightly higher complication risk than those staged. Outcomes remain good, but the immediate recovery period is more demanding.

Surgeon experience and technique: The specific fixation method used for the tibial tuberosity transposition (the most common procedure) affects outcomes. A locking plate and pin technique (PMC12263244) showed no recurrences in 64 of 65 stifles in one study, compared to historical recurrence rates of 5 to 12.4% with traditional methods.

What happens when bilateral MPL needs surgery

When both knees need to be operated on, success rates remain good but the process is more involved.

A University of Minnesota study (PMC4790236) of single-session bilateral MPL repair found a 7.7% reluxation rate and an overall complication rate of approximately 31%, comparable to reported rates for unilateral surgery when both knees are done in one session. Most dogs in the study still achieved good function.

For how success rates change when both knees need surgery, see how success rates change with bilateral MPL.

Knowing what to expect from recovery

Success rates are measured at follow-up, meaning recovery has to go well to achieve the outcome. The published studies measure outcomes weeks to months after surgery, not immediately.

Typical timeline for a successful outcome:

• Week 1 to 2: Strict rest, some swelling, limited weight-bearing expected
• Week 2 to 6: Gradual return to short leash walks; physical therapy often begins
• Week 6 to 12: Progressive activity increase; most dogs noticeably more comfortable
• 3 to 4 months: Most dogs achieving full or near-full function

For full detail on what recovery actually involves, see what recovery looks like after a successful surgery.

Weighing success rates against cost

High success rates only matter if surgery is financially achievable. For the cost breakdown by grade, size, and region, see what successful MPL surgery costs.

For a broader look at the full benefits and risks before committing, see full pros and cons to weigh.

Frequently asked questions

What is the recurrence rate after MPL surgery?

Recurrence rates range from roughly 5 to 21% depending on grade. Lower grades (1 and 2) have recurrence rates below 10% in most studies. Grade 4 cases have the highest reported recurrence at around 21%, though most dogs still achieve a successful overall outcome. Many recurrences are low-grade and don't require revision surgery.

Is MPL surgery more risky in large dogs?

Yes, somewhat. Large dogs have higher recurrence rates after MPL surgery than small dogs, primarily because of greater mechanical forces on the repaired joint. However, success rates remain high overall, and with appropriate surgical technique and post-operative management, large dogs do well.

Can MPL come back after a successful surgery?

Yes. The 5 to 21% recurrence range means this does happen. When it does, many recurrences are lower grade than the original luxation and don't require a second procedure. If you notice your dog skipping again after recovery, contact your vet for evaluation.

Does physical therapy after MPL surgery improve success rates?

Yes. Post-operative rehabilitation helps rebuild the muscle mass that the dog lost during the lameness period and supports healthy healing of the repair. Dogs who complete structured rehabilitation generally achieve better and faster functional recovery than those with rest alone.

The surgery works well for most dogs. The evidence is clear on that. What the evidence also makes clear is that grade matters, timing matters, and what happens during recovery matters. Understanding all three puts you in the best possible position to support a good outcome for your dog.

Resources

• JAVMA. Outcomes and complications following surgical correction of grade IV medial patellar luxation in dogs. avmajournals.avma.org
• NIH/PMC. Positive outcomes after surgical correction of grade IV MPL in small breed dogs. pmc.ncbi.nlm.nih.gov
• NIH/PMC. Clinical results of single-session bilateral medial patellar luxation repair. pmc.ncbi.nlm.nih.gov

When your vet says your dog has Grade 2 MPL, what does that actually mean for your dog's daily life? And is it going to get worse?

The grading system for medial patellar luxation is the single most important factor in determining what treatment your dog needs and what the long-term outlook looks like. Knowing what your dog's grade means puts you in a much better position to ask the right questions and make a confident decision.

Quick answer: MPL is graded 1 to 4 based on how often the kneecap displaces and whether it returns to the groove on its own. Grade 1 is mildest, with the kneecap only luxating when manually pressed. Grade 4 is most severe, with the kneecap permanently displaced. Surgery is typically recommended for Grade 3 and above, and sometimes for Grade 2.

Key takeaways

• Grade 1 is the mildest: The kneecap only moves when a vet manually presses it and returns immediately.
• Grade 2 is the most debated: Intermittent slipping causes skipping; surgery isn't always required.
• Grade 3 means frequent displacement: The kneecap is out more than in; symptoms are usually consistent.
• Grade 4 is the most severe: The kneecap cannot be returned to the groove; surgery is required.
• Higher grades carry more arthritis risk: Each luxation episode stresses the joint and accelerates wear.
• Grades can progress over time: A Grade 2 can become a Grade 3, which is why monitoring matters.

The MPL grading scale: how it works

Veterinarians grade patellar luxation during a physical examination. The vet manually palpates the knee while flexing and extending the joint, assessing how easily the kneecap slips, whether it returns on its own, and how much bone deformity is present.

The four-grade scale was developed to standardize how severity is described and to guide treatment recommendations. Each grade builds on the previous one.

For background on the condition itself, see what medial patellar luxation is before reviewing the grades.

Grade 1: mild and often symptom-free

Grade 1 MPL means the kneecap can be pushed out of the groove manually, but it returns to the correct position immediately when pressure is released. The luxation does not happen on its own during normal movement.

What Grade 1 looks like

Most dogs with Grade 1 MPL show no noticeable symptoms. The condition is often discovered during a routine physical examination when the vet checks the knees as a standard part of the visit.

• The kneecap does not slip during walking, running, or playing
• No skipping or lameness is typically observed
• The dog may not show any signs of discomfort

Treatment for Grade 1

Most Grade 1 cases do not require surgery. The standard approach is:

• Regular monitoring through annual vet exams
• Weight management to reduce joint stress
• Joint-supportive supplements if recommended by your vet
• Low-impact exercise to maintain muscle support around the knee

The main concern with Grade 1 is progression. Not all Grade 1 cases worsen, but monitoring allows your vet to catch any change early.

Grade 2: intermittent and often manageable

Grade 2 is the most commonly diagnosed grade and the one with the most variation in treatment recommendations. The kneecap slips out spontaneously during normal movement but usually returns to the groove on its own, either naturally or when the dog kicks or extends the leg.

What Grade 2 looks like

The classic symptom is intermittent skipping. You'll see your dog lift one back leg for a few steps, then resume normal walking. Some dogs extend or shake the leg to pop the kneecap back into place.

• Intermittent skipping: The most recognizable sign of Grade 2 MPL
• Occasional leg shaking or extending: The dog self-corrects by straightening the leg
• Symptoms may come and go: Some days look completely normal; others involve visible limping

For a full breakdown of what Grade 2 symptoms look like in practice, see symptoms that correspond to each grade.

Treatment for Grade 2

Grade 2 is where treatment decisions get complicated. Some Grade 2 dogs do well with conservative management indefinitely. Others progress to Grade 3 and eventually need surgery.

Factors that push toward surgery for Grade 2:

• Symptoms are frequent or worsening
• The dog's quality of life is visibly affected
• The dog is young with a high risk of progression
• The vet finds significant bone deformity on X-ray

For a detailed look at how to make this specific decision, see the grade 2 surgery decision in detail.

Non-surgical options for Grade 2 include physical therapy, targeted muscle-strengthening exercises, and anti-inflammatory management during flare-ups. See non-surgical options for lower-grade luxation for what that looks like in practice.

Grade 3: frequently displaced and harder to manage

With Grade 3 MPL, the kneecap is outside the groove most of the time. A vet can push it back into place manually, but it slips out again quickly during movement. The dog rarely self-corrects.

What Grade 3 looks like

Dogs with Grade 3 MPL typically show persistent symptoms rather than intermittent ones:

• Consistent lameness or shortened stride in the affected leg
• Visible muscle atrophy in the thigh of the affected limb, because the leg is used less
• A crouched or stilted rear gait, especially after rest
• Joint stiffness, particularly in the morning or after lying down

The constant abnormal contact between the kneecap and the joint surfaces accelerates cartilage wear and increases the risk of cruciate ligament injury.

Treatment for Grade 3

Surgery is recommended for most Grade 3 cases. Without surgery, the joint continues to degrade, arthritis worsens, and the dog's quality of life declines progressively.

For information on what surgery involves and what to expect, see when each grade requires surgery.

Grade 4: permanent displacement

Grade 4 is the most severe form of MPL. The kneecap is permanently out of the groove and cannot be manually repositioned. The bone deformity at this stage is significant.

What Grade 4 looks like

Dogs with Grade 4 MPL have a clearly abnormal gait:

• Constant lameness or leg disuse in the affected limb
• Severe bow-legged or crouched appearance in the rear legs
• Inability to extend the leg fully, because the kneecap is no longer acting as a pulley
• Significant muscle atrophy from disuse of the affected limb

In young puppies with Grade 4 MPL, the bowed-leg appearance is often what prompts the owner to seek veterinary care.

Treatment for Grade 4

Surgery is required. Grade 4 cases often need more extensive bone correction than lower grades, including procedures to reshape the femoral groove or realign the bone. Recovery is longer and the surgical complexity is higher.

How success rates vary by grade is an important part of understanding the surgical decision. See how surgery success varies by grade for what the data shows.

Can MPL grades worsen over time?

Yes. Grades are not fixed. A dog that presents as Grade 2 may progress to Grade 3 over months or years, particularly if:

• The underlying bone deformity is significant
• The dog is growing and the alignment worsens with skeletal development
• Body weight places ongoing stress on the joint

This progression risk is why monitoring is recommended even for dogs with mild grades and minimal symptoms.

How grades compare: quick reference

Frequently asked questions

Can a Grade 2 dog live without surgery?

Many do. Grade 2 dogs with mild, infrequent symptoms and no significant bone deformity can often be managed conservatively for years. Regular vet check-ins allow you to catch any progression early and adjust the plan accordingly.

What causes a grade to progress?

Progression is driven by continued abnormal joint mechanics. Each time the kneecap slips, it wears on the cartilage and the femoral groove. Bone deformity that worsens during growth also drives progression, particularly in young dogs still developing.

Is a higher grade always more painful?

Generally yes, though it's not always proportional. Some Grade 3 dogs appear less bothered than some Grade 2 dogs with frequent luxation episodes. Pain tolerance varies between individual dogs. Your vet's assessment of gait, muscle mass, and joint integrity provides a more complete picture than symptoms alone.

How do vets determine the grade?

Through a hands-on physical examination. The vet manually moves the kneecap while flexing and extending the knee, feeling how easily it displaces, whether it returns spontaneously, and how stable the joint feels overall. X-rays provide additional information about bone alignment and groove depth.

The grade is the starting point, not the whole answer. Two dogs with the same grade can have very different symptoms, very different progression risks, and very different treatment paths. Use the grade as a framework for the conversation with your vet, not as a final verdict on what your dog's future looks like.

Resources

• VCA Animal Hospitals. Luxating Patella in Dogs. vcahospitals.com
• American College of Veterinary Surgeons. Patellar Luxations. acvs.org
• Cornell University College of Veterinary Medicine. Patellar Luxation. vet.cornell.edu

MPL is often described as a small-dog problem. That's mostly accurate, but it's not the whole picture.

Large breeds get MPL too. And when they do, the condition tends to present later, progress differently, and require more complex treatment than it does in a Chihuahua or a Pomeranian. If you have a larger dog and you're trying to understand what an MPL diagnosis means for them specifically, the small-dog information may not fully apply.

This guide covers the key differences between how MPL presents, progresses, and is treated in small and large dogs, so you can understand what to expect for your dog's size. For a full explanation of the condition itself, see what medial patellar luxation is.

Quick summary: Small dogs develop MPL more often, usually from hereditary causes, and typically show symptoms earlier in life. Large dogs develop it less frequently but often with more significant bone deformity, later symptom onset, and more surgically complex cases. Recovery timelines and costs also differ substantially.

Key takeaways

• MPL is 12 times more common in small dogs than large dogs, based on published research.
• Small dogs tend to develop MPL from birth or puppyhood; large dogs often show signs later.
• Large dog cases tend to involve more bone deformity, making surgery more complex.
• Small dogs usually need simpler surgical techniques with shorter recovery times.
• Large dogs need longer rehab, typically 8 to 12 weeks versus 4 to 6 weeks for small breeds.
• Both sizes do well with timely treatment, but delaying surgery increases joint damage in both.

How common is MPL in each size group?

MPL is predominantly a small-dog condition. According to research published in Frontiers in Veterinary Science (2026), patellar luxation occurs approximately 12 times more often in small breeds than in large breeds.

The American College of Veterinary Surgeons confirms that the condition is diagnosed primarily in small dogs, especially toy breeds, though the incidence in large breeds is increasingly recognized.

This difference comes down to anatomy. Small breeds are more likely to inherit the shallow femoral groove, bone angulation, and ligament laxity that causes the kneecap to shift medially. Large breeds can have similar anatomic issues, but they occur less frequently and are sometimes triggered by factors like rapid growth or trauma.

Small dogs: what to expect

Who's most at risk

Small and toy breeds carry the highest genetic risk for MPL. The breeds most commonly affected include:

• Chihuahua
• Pomeranian
• Maltese
• Miniature and Toy Poodle
• Yorkshire Terrier
• Bichon Frise
• Boston Terrier
• French Bulldog

When symptoms appear

In small dogs, MPL is usually present from birth or develops during puppyhood. The anatomic deformities that cause the condition are congenital, meaning they form during skeletal development.

Many small-breed puppies are diagnosed at their first wellness exam or when an owner notices the characteristic skipping gait. Symptoms may be mild early on, then gradually become more frequent as the dog grows and the joint mechanics worsen.

How it typically presents

The most common presentation in small dogs is intermittent skipping: the dog lifts one back leg for a few steps, then resumes normal walking. Many small dogs also affect both knees (bilateral MPL), which can cause a bunny-hopping gait at speed rather than a clear one-sided limp.

For how symptoms differ between breeds, see how MPL grades present differently by breed size.

Surgical approach for small dogs

Small dogs typically require less complex surgery than large breeds. Common procedures include:

• Trochlear sulcoplasty or block recession: Deepening the femoral groove so the kneecap stays in place
• Tibial tuberosity transposition: Realigning the point where the patellar tendon attaches to the shinbone
• Soft tissue imbrication: Tightening the joint capsule on the outer side to prevent the kneecap slipping inward

These procedures are effective in most small breeds and carry a relatively low complication rate when performed before significant arthritis develops.

Recovery for small dogs is typically 4 to 6 weeks before a return to light activity, with full recovery in 8 to 12 weeks.

Large dogs: what to expect

Who's most at risk

While any large breed can develop MPL, some are seen more commonly in veterinary practices:

• Labrador Retriever
• Golden Retriever
• Great Pyrenees
• Akita
• Flat-Coated Retriever

Large breeds may develop MPL from congenital causes, but trauma and rapid growth during puppyhood are also more significant contributors than in small breeds.

When symptoms appear

Large dogs often don't show symptoms of MPL until later in life compared to small breeds. Some are diagnosed as juveniles, but others aren't identified until adulthood, sometimes when lameness becomes persistent enough to prompt a veterinary visit.

This delayed presentation can mean more joint damage has accumulated by the time the diagnosis is made.

How it typically presents

Large dogs with MPL more often present with consistent, weight-bearing lameness rather than the intermittent skipping pattern typical of small breeds. The gait abnormality may be subtler early on, and owners sometimes attribute it to general stiffness or other causes.

Large dogs are also more likely to have concurrent orthopedic issues, such as hip dysplasia or cruciate ligament disease, which can complicate diagnosis and treatment planning.

For a breakdown of how breed size affects the surgery decision specifically, see how breed size affects the surgery decision.

Surgical approach for large dogs

Large dog MPL cases often involve more significant bone deformity, which requires more extensive correction. Procedures used in large dogs may include:

• Corrective osteotomies: Cutting and realigning the femur or tibia to correct rotational or angular deformity
• Femoral derotational osteotomy: Correcting internal rotation of the thighbone
• Deep trochleoplasty techniques: More aggressive groove deepening for severely shallow grooves

These procedures are more complex, carry longer recovery periods, and require more specialized surgical expertise than the techniques typically used in small dogs.

Recovery for large dogs typically takes 8 to 12 weeks of structured rehabilitation, with close monitoring and controlled activity.

Cost differences by size

The surgical complexity difference translates directly into cost. Large-breed MPL surgery is generally more expensive than small-breed surgery.

For specific cost estimates across both size groups, see how breed size affects MPL surgery cost.

Bilateral MPL: more common in small breeds

Bilateral MPL (both knees affected) is considerably more common in small breeds. The genetic and anatomic factors that cause MPL in small dogs tend to affect both legs equally.

Large breeds can also develop bilateral MPL, but it's less common. When it does occur in large breeds, the surgical planning and recovery timeline become considerably more involved.

For information on bilateral cases in both sizes, see how bilateral MPL affects small breeds differently.

Outcomes: do both sizes do equally well?

With timely, appropriate treatment, both small and large dogs generally do well after MPL correction. The key variables are:

• Grade at the time of surgery: Higher grades involve more bone deformity and longer recovery, regardless of size
• Age at treatment: Younger dogs in both size categories tend to recover faster
• Weight: Overweight dogs of any size have higher surgical risk and slower recovery
• Concurrent joint disease: Large breeds are more likely to have other joint conditions that affect outcomes

The main disadvantage for large dogs is that their cases tend to be diagnosed later and require more complex procedures. When caught and treated early, large-dog outcomes are excellent.

Frequently asked questions

My large dog was diagnosed with MPL. Is that unusual?

Not as unusual as it used to be considered. Large-breed MPL is increasingly recognized in veterinary medicine. It simply occurs at a much lower rate than in small breeds and may present differently. Your vet's approach will be tailored to your dog's specific anatomy and grade.

Do large dogs recover from MPL surgery as well as small dogs?

Generally yes, though recovery takes longer and requires more structured rehabilitation. Large dogs with lower-grade MPL that's treated before significant joint damage accumulates often return to full function. Higher-grade cases, especially those with complex bone deformity, may have a longer and more variable recovery.

My small dog has MPL in both knees. Does that change the treatment plan?

Yes. Bilateral cases require decisions about whether to operate on both knees at once or stage the surgeries separately. Most surgeons prefer to address one knee at a time, allowing the dog to use the unoperated leg during recovery. Your vet or surgeon will advise based on your dog's grades and overall condition.

Does breed size affect how quickly MPL progresses?

Small breeds tend to develop and show MPL earlier in life, and the condition may progress during puppy growth spurts. Large breeds may show slower progression but often present with more accumulated joint damage when they're finally diagnosed. Early diagnosis matters in both size categories.

MPL is not just a small-dog condition. But the differences in how it presents, how it's treated, and how long recovery takes are real and meaningful. Understanding those differences helps you ask the right questions and set realistic expectations for your own dog, regardless of whether they fit the typical MPL profile or not.

Resources

• Frontiers in Veterinary Science. Translational Rehabilitation Strategies for Canine Medial Patellar Luxation. frontiersin.org
• American College of Veterinary Surgeons. Patellar Luxations. acvs.org
• VCA Animal Hospitals. Luxating Patella in Dogs. vcahospitals.com